Fuel Pump Circuit Troubleshooting
If you suspect a problem with the fuel pump, check that the fuel pump actually runs; when it is on, you will hear some noise if you listen to the fuel fill port with the fuel fill cap removed. The fuel pump should run for 2 seconds when the ignition switch is first turned on. If the fuel pump does not make noise, check as follows:
  1. Turn the ignition switch OFF.
  1. Remove the under-dash fuse/relay box, then remove PGM-FI main relay 2 (FUEL PUMP) (A) from the under-dash fuse/relay box.
  1. Reinstall the under-dash fuse/relay box.
  1. Turn the ignition switch ON (II).
  1. Measure voltage between PGM-FI main relay 2 (FUEL PUMP) 4P connector terminal No. 3 and body ground.
Is there battery voltage?
YES -
Go to Step 12 .
NO -
Go to Step 6 .
  1. Turn the ignition switch OFF.
  1. Disconnect under-hood fuse/relay box connector D (20P).
  1. Disconnect 23P connector at left side of engine compartment:
  1. Disconnect under-dash fuse/relay box connector G (21P).
  1. Connect under-dash fuse/relay box connector G (21P) terminal No. 4 to body ground with a jumper wire.
  1. Check for continuity between under-hood fuse/relay box connector D (20P) terminal No. 15 and body ground.
Is there continuity?
YES -
NO -
Repair open in the wire between the under-hood fuse/relay box and the under-dash fuse/relay box.■
  1. Measure voltage between PGM-FI main relay 2 (FUEL PUMP) 4P connector terminal No. 1 and body ground.
Is there battery voltage?
YES -
Go to Step 18 .
NO -
Go to Step 13 .
  1. Turn the ignition switch OFF.
  1. Disconnect the inertia switch 3P connector.
  1. Connect inertia switch 3P connector terminals No. 1 and No. 3 with a jumper wire.
  1. Turn the ignition switch ON (II).
  1. Measure voltage between PGM-FI main relay 2 (FUEL PUMP) 4P connector terminal No. 1 and body ground.
Is there battery voltage?
YES -
NO -
  • Replace the No. 2 FUEL PUMP (15 A) fuse in the under-dash fuse/relay box.■
  • Replace the under-dash fuse/relay box.■
  • Repair open in the wire between the inertia switch and the under-dash fuse/relay box.■
  1. Turn the ignition switch OFF.
  1. Connect PGM-FI main relay 2 (FUEL PUMP) 4P connector terminal No. 4 to body ground with a jumper wire.
  1. Jump the SCS line with the HDS.
  1. Disconnect ECM connector A (44P).
  1. Check for continuity between body ground and ECM connector terminal A15.
Is there continuity?
YES -
Go to Step 23 .
NO -
Repair open in the wire between PGM-FI main relay 2 (FUEL PUMP) and the ECM (A15).■
  1. Remove the under-dash fuse/relay box, then reinstall PGM-FI main relay 2 (FUEL PUMP).
  1. Connect ECM connector terminal A6 to body ground with a jumper wire.
  1. Turn the ignition switch ON (II).
  1. Measure voltage between ECM connector terminal A15 and body ground.
Is there battery voltage?
YES -
Go to Step 28 .
NO -
Replace PGM-FI main relay 2 (FUEL PUMP).■
  1. Turn the ignition switch OFF.
  1. Reconnect ECM connector A (44P).
  1. Turn the ignition switch ON (II), and measure voltage between under-dash fuse/relay box connector F (34P) terminal No. 10 and body ground within 2 seconds.
Is there battery voltage?
YES -
Update the ECM if it does not have the latest software, or substitute a known-good ECM, then recheck. If the symptom/indication goes away with a known-good ECM, replace the original ECM. ■
NO -
Go to Step 31 .
  1. Turn the ignition switch ON (II), and measure voltage between under-dash fuse/relay box connector F (34P) terminal No. 10 and body ground after 2 seconds.
Is there battery voltage?
YES -
Go to Step 32 .
NO -
  1. Turn the ignition switch OFF.
  1. Turn the ignition switch ON (II), and measure voltage between fuel tank unit 4P connector terminal No. 2 and body ground within 2 seconds.
Is there battery voltage?
YES -
Go to Step 39 .
NO -
Go to Step 35 .
  1. Turn the ignition switch OFF.
  1. Remove PGM-FI main relay 2 (FUEL PUMP).
  1. Connect PGM-FI main relay 2 (FUEL PUMP) 4P connector terminals No. 1 and No. 2 with a jumper wire.
  1. Turn the ignition switch ON (II), and measure voltage between fuel tank unit 4P connector terminal No. 2 and body ground within 2 seconds.
Is there battery voltage?
YES -
Replace PGM-FI main relay 2 (FUEL PUMP).■
NO -
Repair open in the wire between PGM-FI main relay 2 (FUEL PUMP) and the fuel tank unit 4P connector.■
  1. Turn the ignition switch OFF.
  1. Check for continuity between fuel tank unit 4P connector terminal No. 4 and body ground.
Is there continuity?
YES -
NO -
Repair open in the wire between the fuel tank unit 4P connector and G601.■